There is too often the situation when old version of WordPress is used and no one performs updates. No update of WordPress makes it difficult for plugin developers (such as Kocuj Sitemap) to do technical support and backward compatibility. Therefore, I have decided that from version 2.0.0 of Kocuj Sitemap plugin only 2 versions of WordPress will be supported – the newest and previous. For example, when the latest WordPress version is 4.3, then versions 4.2 and 4.3 will be supported. I have to admit that an attempt to support very old versions of WordPress was one of the main reasons for the lack of any update for the Kocuj Sitemap plugin.
But what should do people with old versions of WordPress? The answer is simple – to update.
Please be aware that an outdated version of WordPress is nothing more but trouble. Sooner or later your website will get hacked. Therefore, WordPress update process should be performed as often as possible.
But why people do not update their WordPress installations? There are often the same few reasons. I will try to argue with them below.
Plugin, which we are using, will stop working
If a plugin author abandoned it and no longer provides updates, you should look for another plugin that provides the same or similar functionality. You possibly can, in order to repair this, hire a specialist who will repair the plugin, find another plugin or write his own solution.
Sometimes it turns out that plugin, that is not marked by its author as working in the latest version of WordPress, works fine. So you should test it.
Theme or the entire site will be inoperable
If your theme is not working correctly in the latest version of WordPress, please contact with its author and determine the conditions for correcting these bugs. Alternatively, as in the case of plugin, you may employ a specialist, who will repair a theme.
My changes in WordPress core will be lost
Never, ever, do not change anything in WordPress core! At first update of WordPress core, all your changes will be lost!
If you need some change in WordPress, you should find plugin with the appropriate functionality.
Summary
If, despite these arguments, you still want to have the old version of WordPress, then you will not can use latest versions of Kocuj Sitemap plugin.